1. Field of the Invention
The present invention relates to a novel process for preparing fiber-reactive formazan dyes by diazotizing a protected hydroxyphenylenediamine compound, coupling with a hydrazone compound, metallizing, eliminating the protective group, and reacting with a halotriazine and optionally thereafter with an amine or a hydroxy compound. The present invention also relates to novel aminophenols.
2. Description of the Background
EP-A-280 139 discloses preparing aminoformazan dyes by reacting the arylhydrazone with a diazotized o-hydroxyaminobenzene. Amino groups to be present in the end, product must be protectively acetylated before the reaction and the protective acetyl group must be reeliminated afterwards.
However, the alkaline hydrolysis of the protective group requires high alkali concentrations, high reaction temperatures and long reaction times.
A further disadvantage of existing processes is that, prior to the reaction with hydrolysis-sensitive fiber-reactive components, eg. with halotriazines, the alkaline solution must first be neutralized, which produces appreciable amounts of salt.